Apparatus and method for minimally invasive surgery using rotational cutting tool

ABSTRACT

An apparatus and method for minimally invasive surgery using a cutting tool with rotational cutting edges. The surgical instrument includes a tube having a distal end and a cutting edge at the distal end. A handle is attached to the proximal end of the tube. Within the tube is a shaft having a longitudinally extending blade at its distal end that is adjacent to the distal end of the tube. The blade is revolvable about the longitudinal axis of the instrument to provide rotational cutting action. One or both of the blade and the cutting edge on the tube can be electrically energized to provide for electrocauterization of the body tissue being cut.

This is a continuation of application with Ser. No. 09/522,254 filedMar. 9, 2000.

FIELD OF THE INVENTION

The invention relates generally to minimally invasive surgical tools andtechniques and, particularly, to a method and apparatus for cutting bodytissue using a bipolar or monopolar electrocautery tool with rotationalcutting blades.

BACKGROUND OF THE INVENTION

Minimally invasive surgery such as laparoscopic, endoscopic,hysteroscopic, and arthroscopic surgery is becoming more widely usedbecause it is less traumatic to the patient, generally involves lesshospitalization time, less discomfort and less risk to the patient, andcan be less costly than traditional open surgery. A minimally invasivesurgical procedure is typically performed by making a small incision inthe patient which provides access to the area to be treated. A trocarsheath may be inserted in the incision and an airtight seal around thetrocar established. The area in the body which is to be treated may bedissected from surrounding tissue by a dissecting tool such as a balloondissection tool. The dissecting tool is then removed and an elongatedsurgical tool is inserted through the trocar sheath. Access to the areato be treated may be through one or more trocar sleeves which may beconfigured to permit the slidable insertion of the endoscopes andsurgical instruments without compromising the airtight seal around thetrocar sheath.

Minimally invasive surgery is generally performed using elongatedinstruments slidably inserted through the trocar sleeves, or if thesurgery is performed in a naturally occurring body cavity, such as theuterus, the instruments may be inserted through a relatively narrow bodyorifice such as the cervix. In any event, the operator must perform thesurgical manipulations using a tool such as a scalpel or a needlegripper on the end of the elongated surgical instrument. The tool isremotely located from the operator's hands and confined within arelatively small cavity created for the operation. The elongatedsurgical tool is often endoscopic, i.e., it includes a camera by whichthe surgeon can observe the area in the body that is to be treated.

FIG. 1 shows prior art pivoting scissors 190 that can be used forsurgery. Pivoting blades 192 and 194 of scissors 190 are pivotallyattached to an elongated shaft 196 at a pivot point 198. The scissors190 have a width W when blades 192 and 194 are fully open. The pivotingscissors 190 can be controlled by cables (not shown) that extend throughshaft 196. The cables are connected to a pistol grip 191 at the oppositeend of shaft 196 that has a lever 193 that is squeezed by the operator.The lever 193 has a lever arm which produces a magnification of theforce applied by the operator at the pistol grip 191 and transmittedthrough the cables to the blades 192 and 194. The pivoting scissorsdesign of FIG. 1 does not provide an opening or a lumen through shaft196 for an auxiliary instrument such as an endoscope or an irrigation orsuction cannula. Thus, pivoting scissors 190 generally do not allowadditional instruments to be used through the same incision.

The surgical manipulations must be performed while observing theprocedure with an endoscope or other imaging device. The imaging devicemay be inserted through a separate trocar into the distal cavity.Alternatively, the endoscope may be contained within a surgical tubewhich also contains surgical instruments. The image from the endoscopeis often displayed on a video screen and generally results in an imagehaving little or no depth perception.

One example of an increasingly common minimally invasive surgicalprocedure involves the “harvesting” of a saphenous vein as part of aheart bypass operation. The saphenous vein can be removed from the legof a heart bypass patient and then used on the heart to provide thebypass vessels. One method of harvesting a saphenous vein involvesmaking an incision along nearly the entire length of the patient's legand then removing the saphenous vein by open surgery. This technique cancreate great discomfort to the patient and increase the risk ofcomplications because of the length of the incision and the opensurgery. Also, after such a surgery, the time required for the patientto heal is relatively long.

Another technique commonly used for saphenous vein harvesting involves aminimally invasive procedure that requires two incisions; the firstincision being either at the knee area or the ankle area, and the secondbeing at the top of the patient's leg near the groin area. Through oneincision, the surgeon inserts a first instrument such as the elongatedscissors shown in FIG. 1, and through the other incision, the surgeoninserts a second instrument such as an elongated clamp or a ligatingtool. After inserting the two instruments, the surgeon holds oneinstrument in one hand and the other instrument in the other hand. Thesurgeon then simultaneously manipulates the instruments to perform thesurgical procedure. For instance, the surgeon holds a piece of tissuesuch as a blood vessel with the clamp, and then cuts the blood vesselwith the scissors. This technique, even though it is less invasive thanan open incision, is cumbersome for the surgeon to accomplish becausethe surgeon must manipulate two separate instruments from two differentdirections or positions.

Also, the two-incision technique is difficult because the surgeon mustobserve the instruments and tissue in the body cavity from two differentdirections. When each instrument is accompanied by an endoscope, eachendoscope provides an image of the end of the other tool as it movestoward the endoscopic lens from the opposite direction. Even in asingle-tool procedure in which the elongated surgical instrument isinserted through the first incision and an endoscope is inserted throughthe second incision, the endoscope provides an image of the end of theelongated surgical instrument as the surgical instrument is movingtoward the endoscope. The surgeon must interpret this counter-intuitiveimage while manipulating the surgical instrument.

When a saphenous vein is harvested using any of the aforementionedtechniques, the main vessel that will be removed must be separated fromtributary vessels that branch off the saphenous vein along its length.Before the vessels are cut, they are typically ligated by applying aclip, for example. After the tributaries are cut away from the saphenousvein, they must be permanently closed. This can be accomplished bysuturing, clipping, or cauterizing. Each of these ligation techniquesrequires a separate step, which increases the time required for thesurgery.

Surgical procedures can be improved so as to decrease patient discomfortand hospitalization time by techniques that combine the cutting andligating or cauterizing procedures. One such technique iselectrocautery. An electrocautery tool typically includes a scalpel orthe blades of scissors that are electrically energized. Electrocauterycan be used to simultaneous cut and cauterize tissue.

Methods for improving minimally invasive surgical procedures includedecreasing the size of the instrument or performing the procedurethrough fewer incisions. Decreasing the size of the instrument orreducing the number of incisions reduces the damage caused to thepatient's body and tissues, thus reducing the time required for healing.

SUMMARY OF THE INVENTION

An embodiment of the present invention includes a surgical instrumenthaving a tube and a shaft within the tube. The tube and the shaft eachhave a distal end and a proximal end. The distal end of the tubeincludes a cutting edge, and the distal end of the shaft includes ablade. Either the blade or the shaft is rotatable with respect to theother such that the blade cooperates with the cutting edge to cut bodytissue.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of prior art surgical scissors;

FIG. 2A is a side elevational view of a surgical instrument inaccordance with one embodiment of the invention;

FIG. 2B is a cross sectional view of the surgical instrument of FIG. 2A;

FIG. 2C is a cross sectional view of the surgical instrument of FIG. 2Btaken along line 2—2 of FIG. 2B;

FIG. 3 is a partial cross sectional view of a surgical instrument inaccordance with an alternate embodiment of the invention;

FIG. 4 is a perspective view of a surgical instrument in accordance withanother alternate embodiment of the invention;

FIG. 5 is an enlarged partial view of the rotational cutting blades ofthe surgical instrument of FIG. 2A;

FIG. 6 is an end view of the instrument of FIG. 5 taken along line 6—6of FIG. 5;

FIG. 7A is a partial perspective view of rotational cutting blades ofone embodiment of the invention;

FIG. 7B is an end view of the rotational cutting blades of FIG. 7A;

FIG. 8A is a partial perspective view of rotational cutting blades ofanother embodiment of the invention;

FIG. 8B is an end view of the rotational cutting blades of FIG. 8A;

FIG. 9A is a partial perspective view of rotational cutting blades ofanother embodiment of the invention;

FIG. 9B is an end view of the rotational cutting blades of FIG. 9A;

FIG. 10A is a partial perspective view of rotational cutting blades ofanother embodiment of the invention;

FIG. 10B is a side view of the rotational cutting blades of FIG. 10A;

FIG. 10C is an end view of the rotational cutting blades of FIG. 10A;

FIG. 11A is a partial perspective view of rotational cutting blades ofanother embodiment of the invention;

FIG. 11B is an end view of the rotational cutting blades of FIG. 11A;

FIG. 12A is a partial perspective view of rotational cutting blades ofanother embodiment of the invention;

FIG. 12B is a side view of the rotational cutting blades of FIG. 12A;

FIG. 13A is a partial perspective view of rotational cutting blades ofanother embodiment of the invention;

FIG. 13B is an end view of the rotational cutting blades of FIG. 13A;

FIG. 14A is a partial perspective view of rotational cutting blades ofanother embodiment of the invention;

FIG. 14B is an end view of the rotational cutting blades of FIG. 14A;

FIG. 15 is a partial perspective view of a surgical instrument ofanother embodiment of the invention;

FIG. 16 is a sectional view of the surgical instrument of FIG. 15;

FIG. 17 is a side view of a surgical instrument of another embodiment ofthe invention; and

FIG. 18 is a cross sectional view of the surgical instrument of FIG. 17.

DETAILED DESCRIPTION

FIG. 2A shows an embodiment of a surgical instrument 100 of theinvention. Surgical instrument 100 includes a tube 110 and a shaft 130.Tube 110 has a distal end 112 and a proximal end 114. Similarly, shaft130 includes a distal end 132 and a proximal end (not shown). Distal end112 of tube 110 includes an outer blade 120 extending longitudinallytherefrom. Distal end 132 of shaft 130 includes an inner blade 140extending longitudinally therefrom. Shaft 130 is rotatably disposedwithin tube 110 such that inner blade 140 is revolvable about thelongitudinal axis of tube 110. As shaft 130 rotates, causing inner blade140 to revolve about the longitudinal axis, inner blade 140 cooperateswith outer blade 120 to create a rotational cutting action between theblades.

Surgical instrument 100 preferably includes a handle 150. As shown inFIG. 2A, handle 150 includes an elongated grip 152. Handle 150 can beconfigured to provide an ergonomic holding and controlling location forthe operator of surgical instrument 100. Handle 150 is operativelyassociated with the proximal ends of tube 110 and tubular shaft 130.

Also, handle 150 provides a body on which a cutting control 151 can bedisposed. Cutting control 151 can be configured, as described in furtherdetail below, such that the operator of surgical instrument 100 canselectively revolve inner cutting blade 140 to perform the cutting ofbody tissue during surgery. Also as described in further detail below,control 151 can be operatively associated with either tube 110 or shaft130 to move either inner cutting blade 140 or outer cutting blade 120,or both, with respect to the other.

Surgical instrument 100, as shown in FIG. 2A, can also be adapted foruse as an electrocautery cutting tool. Either one of the outer blade 120or inner blade 140, or both, can be adapted to be electricallyenergized. Electrical connector 160 can be provided extending fromhandle 150, for example, to provide a connection to a source ofelectricity (not shown). In the case of the surgical instrument 100having electrically energized inner and outer blades, an innerinsulating sleeve 136 is provided to electrically isolate tube 110 fromshaft 130. An outer insulating sleeve (not shown) can also be providedto electrically isolate tube 110 from the body of the patient or fromother instruments with which tube 110 might come into contact during thesurgical procedure. The insulating sleeves can be made of anon-conductive material such as plastic.

In the case where one of either outer blade 120 or inner blade 140 iselectrically energized, the surgical instrument 100 is a monopolarcutting tool having rotational cutting blades (i.e. a monopolarrotational cutting tool). When both outer blade 120 and inner blade 140are electrically energized, the surgical instrument 100 is a bipolarrotational cutting tool. In either case, surgical instrument 100 can beused to cut and ligate blood vessels in a single step without the needfor other tools or other process steps such as suturing, clipping, orthe like.

During use, as inner blade 140 is revolved such that inner bladecooperates with outer blade 120, the body tissue disposed between outerblade 120 and inner blade 140 is cut by the mechanical rotationalcutting action of the two blades and can be, at the same time,electrically cauterized. If the tissue being cut is a body vessel, forexample, the vessel is simultaneously ligated by the electrocauteryfeature, if provided, of the rotational cutting tool. In use, surgicalinstrument 100 is inserted into an incision previously made in thepatient. Distal end 102 of the instrument 100 is inserted into theincision and can be either inserted through a trocar sheath or directlyinto the patient.

FIG. 2B shows a cross-sectional view of surgical instrument 100.Surgical instrument 100 includes cutting control 151 on handle 150.Handle 150 includes a housing 153 having a longitudinal, cylindricalextension 159. Housing 153 includes grip 152. In the example shown inFIG. 2B, cutting control 151 includes shaft controller body 156 and ring157 rotatably mounted on cylindrical extension 159. Ring 157 is coupledto shaft 130. Alternatively, cutting control 151 may be a lever coupledto shaft 130 and extending radially from shaft 130 through housing 153.Cutting control 151 can also be a knob, handle, or the like. Cuttingcontrol 151 is actuated by the operator by rotating shaft controller 156or moving a lever (not shown) such that torque is applied to shaft 130to rotate shaft 130 about its longitudinal axis.

FIG. 2B shows handle 150 including a seal 162 at the most proximal endof housing 153 around opening 158 b. Seal 162 can be provided such thathousing 153 and tube 110 operate as a secondary trocar. An auxiliaryinstrument 170, such as an endoscope, an irrigation or suction cannula,or a grasper can be inserted through opening 158 b while seal 162prevents fluids from exiting the body through lumen 138 and opening 158a and 158 b of handle 150. Also, seal 162 can stop air or contaminantsfrom entering the interior of instrument 100 from the outside.

FIG. 2C is a cross-sectional view of cutting control 151 of FIG. 2B.FIG. 2C shows ring 157 mounted rotatably around the cylindricalextension 159 of housing 153 (FIG. 2B). As described in further detailbelow, an opening 158 a extends through cylindrical extension 159, andan auxiliary instrument 170 can be inserted through opening 158 a.

Referring again to FIG. 2B, tube 110 is fixedly attached to handle 150and shaft 130 rotatable relative to tube 110. Alternatively, shaft 130can be fixedly attached to handle 150 and tube 110 can be rotatableabout its longitudinal axis relative to shaft 130. In this case, cuttingcontrol 151 can be configured to be a tube controller.

Handle 150 of FIG. 2B includes housing 153 that is generally hollow anddefines openings 158 a and 158 b. Opening 158 a is located at the distalend of housing 153 and extends through cylindrical extension 159.Opening 158 b is located at the proximal end 103 of housing 153. Opening158 a is in communication with lumen 138 of tubular shaft 130. Openings158 a, 158 b, and lumen 138 provide access through the instrument 100 tothe distal end 132 of tubular shaft 130. An auxiliary instrument 170 canbe inserted through opening 158 and further through lumen 138. Examplesof an auxiliary instrument 170 are a suction or irrigation cannula, animaging device, or a sensor.

The distal end 102 of surgical instrument 100 has a diameter D, as shownin FIG. 2B. The diameter D of the distal end 102 can be sized such thatbody vessels of many sizes may be cut. The surgical instrument 100rotationally cuts body tissue without disturbing surrounding tissue thatis outside the circumference of the tool. The rotational blades ofsurgical instrument 100 do not expand or spread beyond the circumferencedefined by diameter D.

In contrast, the pivoting blades of the scissors 190 of FIG. 1 must bespread apart in order to be positioned around the tissue to be cut. Whenthe blades of the scissors 190 are spread apart, the surrounding tissuecan be damaged. Surgical instrument 100 does not cause as much damage tosurrounding tissue because its rotational blades are rotated within afixed circumference rather than spread apart. Also, the rotationalcutting tool design of the example of FIGS. 2A and 2B provides a betterfeel and control of the cutting action for the operator of theinstrument because of the direct control of the rotating blade throughthe cutting controller 151.

Referring again to FIGS. 2A and 2B, tube 110 and shaft 130 are coaxial,having a common longitudinal axis 119. As described with reference toFIGS. 2A and 2B, tube 110 and shaft 130 can be rotated about axis 119(FIG. 2B) to perform the rotational cutting. Shaft 130 is rotatablydisposed within tube 110 such that the outer surface of shaft 130 is inclose proximity to the inner surface of tube 110. Since inner blade 120and outer blade 140 extend longitudinally from tube 110 and shaft 130,respectively, the blades also become closely proximate to each otherwhen either tube 110 or shaft 130 is rotated relative to the other. Therotational cutting action of the blades is described in further detailbelow.

FIGS. 2A and 2B show one embodiment of the invention in which the tube110 and shaft 130 are coaxial. The rotational cutting action of thesurgical instrument of the invention does not require that the tube 110and shaft 130 be coaxial, however. The rotational cutting action isperformed by one blade revolving about a longitudinal axis with respectto another blade. The revolving blade need not extend from a coaxialtube or shaft, as described below with reference to FIG. 3.

FIG. 3 shows another embodiment of a surgical instrument 200 of theinvention. Instrument 200 includes tube 210 and shaft 230 within tube210. Shaft 230 is shown in FIG. 3 as being solid, but can alternativelybe tubular. Tube 210 has a first axis 219 and shaft 230 has a secondaxis 239. The axes of the tube 210 and shaft 230 are displaced from eachother. Tube 210 includes an outer blade 220 extending longitudinallyfrom its distal end 212. Likewise, shaft 230 includes an inner blade 240extending longitudinally from its distal end 232. Inner blade 240 andouter blade 220 operate in a similar fashion as the embodimentpreviously described with respect to FIGS. 2A and 2B.

In FIG. 3, however, shaft 230 is fixedly attached to handle 250 whiletube 210 is rotatable about its axis with respect to handle 250 andshaft 230. That is, while shaft 230 including inner blade 240 remainfixed relative to handle 250, tube 210 can be rotated by rotatingcutting control 251 which is coupled to tube 210. When cutting control251, and thus tube 210 including inner blade 220, is rotated, outerblade 220 and inner blade 240 become operatively engaged so as to cutthe body tissue (not shown) that is located between the outer blade 220and inner blade 240. The body tissue to be cut is situated transverselybetween the blades by the operator of surgical instrument 200 by movingthe instrument into position as desired.

In an alternate embodiment, tube 210 can be fixed and shaft 230 can berevolvable about longitudinal axis 239. Yet another embodiment of asurgical instrument 200 can include a tube 210 rotatable about axis 219and a shaft 230 revolvable about axis 219.

Handle 250 of FIG. 3 can define opening 258 so that an auxiliaryinstrument (not shown) can be inserted through surgical instrument 200,as similarly described with respect to the instrument of FIG. 2B. Handle250 includes a cylindrical extension 259 through which opening 258 isdefined. Cutting control 251 is a tube controller 254 that is coupled totube 210. It should be noted that tube controller 254 can comprise ring255 rotatably disposed and surrounding extension 259 as shown in FIG. 3.Alternatively, tube controller 254 can be a lever (not shown) fixedlyattached to tube 210.

FIG. 4 shows with another embodiment of a surgical instrument 300 of theinvention. Surgical instrument 300 also includes tube 310 and shaft 330.Shaft 330 can be either tubular and coaxial, similar to shaft 130 ofFIG. 2B, or can have an axis displaced from the axis of tube 310,similar to shaft 230 of FIG. 3. In either case, FIG. 4 shows a surgicalinstrument 300 having a handle 350 that includes two tube controllers354 and 356. The two tube controllers allow the operator of theinstrument 300 to rotate the tube 310 from at least two hand position.

In any of the embodiments described herein, the tube and the shaft arerotatable with respect to each other such that the inner blade isrevolvable about the central axis of the distal end of the instrument,which generally (i.e., within manufacturing tolerances) corresponds tothe central longitudinal axis of the tube. Within the rotatingmechanism, detents or a frictional mechanism can be provided to hold thetube or shaft in position once the operator rotates the tube or shaft.

FIG. 5 shows an embodiment of the distal end 102 of the surgicalinstrument 100. Tube 110 includes outer blade 120 at its distal end 112.Outer blade 120 extends longitudinally from distal end 112 of tube 110.As shown in FIG. 5, outer blade 120 is an extension of the wall of tube110. Outer blade 120 need not be integral with tube 110, however. Outerblade 120 can be a separate piece that is either fixedly or removablyattached to distal end 112 of tube 110. Inner blade 140 can be similarlyattached to shaft 130 or can be integral with shaft 130. When outerblade 120 or inner blade 140 are removable, they can be replaced withnew inner or outer blades that can have different shapes orconfigurations.

Outer blade 120 includes a first outer cutting edge 122 and a secondouter cutting edge 124 (shown in FIG. 6) on the opposite lateral edge ofouter blade 120. The first and second outer cutting edges are laterallydisposed on either side of outer blade 120 and, in the example shown inFIG. 5, extend longitudinally from tube 110.

FIG. 5 also shows shaft 130 coaxially located within tube 110.Insulating sleeve 136 can be provided between tube 110 and shaft 130 toelectrically isolate tube 110 from shaft 130 when either or both areelectrically energized. Inner blade 140 extends longitudinally fromdistal end 132 of shaft 130. Outer blade 120 and inner blade 140 areoperatively associated such that they have a rotational cutting action.

Inner blade 140 has a first inner cutting edge 142 and a second innercutting edge 144. When shaft 130 is rotated within tube 110, inner blade140 revolves about the longitudinal axis 119 of tube 110. Thus, as innerblade 140 is revolved to bring first inner cutting edge 142 intooperative contact with first outer cutting edge 122, the two cuttingedges contact each other at a moving cutting point beginning closest tothe most proximal end of the intersection of the cutting edges. As theinner blade 140 revolves further in the counter-clockwise direction asviewed from the end of instrument 100 in FIG. 5, the cutting point movesdistally along the engaged inner and outer cutting edges.

For illustrative purposes, outer blade 120 and inner blade 140 are shownhaving first and second cutting edges. It should be noted, however, thateach blade can be provided with only one cutting edge in an alternateembodiment.

FIG. 6 illustrates the cutting of a vessel or body tissue 104 at thedistal end 102 of the instrument. In the example of FIG. 6, inner blade140 is revolvable in the direction of the arrows 165 as the shaft isrotated about the longitudinal axis of the tube 110. Outer blade 120remains stationary in the example of FIG. 6. First outer cutting edge122 and first inner cutting edge 142 are shown in the cutting position.Second outer cutting edge 124 and second inner cutting edge 144 areshown in a separated or open position.

The surgical instrument 100 can provide two inner and two outer cuttingedges as illustrated in FIGS. 5 and 6 so that the operator can selectthe location of the cut of the body tissue 104 without rotating theentire instrument 180 degrees. In an alternate embodiment, second outercutting edge 124 and second inner cutting edge 144 can be replaced byinner and outer clamping surfaces. In yet another alternate embodiment,one of the inner or outer cutting edges can be replaced by an anvil suchthat the respective 10 outer or inner cutting edge cuts the body tissueby being forced against the anvil.

FIGS. 7-13 illustrate various different embodiments of the distal end ofthe surgical instrument of the invention.

FIGS. 7A and 7B show distal end 402 including tube 410 having a distalend 412 and an outer blade 420 extending longitudinally from distal end412. Inner blade 440 is also shown in FIGS. 7A and 7B.

FIG. 7A shows outer blade 420 having a first outer cutting edge 422.First outer cutting edge 422 of the example of FIG. 7A is formed, forexample, by making a curved cut transversely across tube 410. The curveformed by first outer cutting edge 422 follows a point that travelslongitudinally along the surface of tube 410 while also travelingspirally around tube 410. Likewise, second outer cutting edge (notshown) follows a curve that is symmetrical to that of first outercutting edge 422.

FIG. 7B shows inner blade 440 having a generally semi-circular crosssection. The chord of the cross section of inner blade 440 travelsthrough or near the central axis of the tube 410. Inner blade 440, asshown in FIG. 7A, extends generally longitudinally from the shaft (notshown) similarly to previously described embodiments. Inner blade 440includes first inner cutting edge 442 and second inner cutting edge 444.First inner cutting edge 442 is operatively associated with first outercutting edge 422, and second inner cutting edge 444 is operativelyassociated with second outer cutting edge 424.

FIGS. 8A and 8B show yet another embodiment of a distal end 502 of asurgical instrument of the invention. Inner blade 540 extendslongitudinally from a shaft (not shown) similarly to previouslydescribed embodiments. As shown in FIG. 8B, inner blade 440 has agenerally rectangular cross section. Inner blade 540 also revolvesaround a central axis. First inner cutting edge 542 and second innercutting edge 544 are located on the outer-most corners of therectangular cross section of inner blade 540. As observed from the endof distal end 502, the cutting edges of inner blade 540 follow the innercircumference of tube 510 when inner blade 540 is revolved around thecentral axis. In this manner, inner blade 540 cooperatively engagesouter blade 520 to provide the rotational cutting action.

FIGS. 9A and 9B show still another embodiment of a distal end 602 of asurgical instrument of the invention. Inner blade 640, as shown in FIG.9A, extends generally longitudinally from a shaft (not shown). Innerblade 640 has a first inner cutting edge 642 and a second inner cuttingedge 644. First and second cutting edges 642 and 644 extendlongitudinally along inner blade 640 and toward each other at thedistally terminal point of blade 640 to form a roughly triangularprofile.

FIG. 9B shows an end view of distal end 602. Inner blade 640 is shown inFIG. 9B as having a somewhat rectangular cross section. Inner blade 640has first inner cutting edge 642 and second inner cutting edge 644disposed at its outer-most corners. Inner blade 640 of FIGS. 9A and 9Brevolves around the longitudinal axis of the tube 610, in a similarfashion as previously described embodiments.

FIGS. 10A-10C show another embodiment of a distal end 702 of a surgicalinstrument of the invention. Tube 710 includes distal end 712 from whichouter blade 720 longitudinally extends. As shown in FIG. 10B, the outerblade includes a first cutting edge 722 that has a curved profile thatcan be formed by cutting trarversely across tube 710.

FIGS. 10A-10C show inner blade 740. As shown in FIG. 10C, inner blade740 has a partial-circular cross section. The chord of the cross sectionis displaced from and is transverse to the longitudinal axis of tube710. As shown in FIG. 10C, inner blade 740 includes a first innercutting edge 742 and a second inner cutting edge 744 at the points wherethe chord of the cross section meets the outer circumference of innerblade 740.

FIGS. 11A and 11B show still another embodiment of a distal end 802 of asurgical instrument of the invention. FIG. 11B shows outer blade 820 andinner blade 840 having arced cross sections which are each approximatelya quarter of a circle.

FIGS. 12A and 12B show yet another embodiment of a distal end 902 of asurgical instrument of the invention. FIGS. 12A and 12B show outer blade920 and inner blade 940, each extending at an angle away from thelongitudinal axis of tube 910. The outwardly extending inner and outerblades of the embodiment of FIGS. 12A and 12B provide a larger spacebetween the blades so that a larger piece of body tissue or a largerdiameter body vessel can be cut.

FIGS. 13A and 13B show another embodiment of the surgical instrument ofthe invention having a distal end 180. Distal end 180 provides aconfiguration that can be used for biopsy collection. Distal end 180includes an outer blade 181 which includes a first scoop 182. Firstscoop 182 has a first cutting edge 183. Inner blade 185 likewiseincludes a second scoop 186. Second scoop 186 has a second cutting edge187. The first and second scoops are operatively associated to collectthe biopsy sample when the shaft (not shown) is rotated within the tube186.

FIG. 13A shows first cutting edge 183 and second cutting edge 187 beingserrated. It should be noted that any of the cutting edges describedherein can be serrated.

FIGS. 14A and 14B show another embodiment of a surgical instrument 1200of the invention having a distal end 1202. FIG. 14A shows tube 1210having shaft 1230 within its lumen. Tube 1210 includes outer blade 1220extending from its distal end, and shaft 1230 includes inner blade 1240extending from its distal end. Outer blade 1220 has an outer cuttingedge 1222, and inner blade 1240 has an inner cutting edge 1242.

Surgical instrument 1200 is a bipolar electrocautery instrument thatincludes rotational cutting features. The electric energy forelectrocautery is provided through electrodes that are on the inner andouter blades, rather than through the blades themselves. The electrodesdo not contact each other, but provide an electric potential in thevicinity of the cutting edges of the blades. In this configuration, thecutting edges of the inner and outer blades can contact each other toprovide mechanical cutting action without causing an electrical short.At the same time, electrocautery can be provided by instrument 1200.

As shown in FIGS. 14A and 14B, an outer electrode 1221 is provided onthe exterior surface of the outer blade 1220 and can be extended alongthe outer surface of the tube 1210. An inner electrode 1241 is providedon the inner surface of the inner blade 1240. Alternatively, electrodescan be provided on both inner and outer surfaces of each of the outerand inner blades. As shown in FIG. 14A, body tissue 1204 is cut bymechanical cutting action as outer cutting edge 1222 and inner cuttingedge 1242 are rotated toward each other.

A dielectric or insulating material (not shown) is preferably providedbetween the outer electrode 1221 and the outer blade 1220. Similarly, adielectric or insulating material is provided between the innerelectrode 1241 and the inner blade 1240. The dielectric or insulatingmaterial can be an adhesive material that attaches the electrodes to theblades.

FIG. 15 shows the distal end 1002 of another embodiment of a surgicalinstrument of the invention. Distal end 1002 includes a bendable section1006 located slightly proximate to the distal end 1012 of tube 1010. Thebendable section 1006 can be as short or as long along the length of thetube 1010 as desired for any particular application. For example, if theinstrument 1000 is to be used in a part of a body of a patient that isparticularly difficult to access, it is desirable to have tube 1010 asflexible along as much of its length as possible. The embodiment of thepresent invention exemplified by surgical instrument 1000 of FIG. 15 canincorporate an articulating mechanism (not shown) such that distal end1002 can be moved transversely by controls on the handle of theinstrument.

FIG. 16 shows an example of the bendable section 1006 of the instrument1000 of FIG. 15. FIG. 16 shows tube 1010 having a distal end 1012 and anouter blade 1020 extending longitudinally from distal end 1012. Shaft1030 is coaxial with tube 1010. Shaft 1030 includes inner blade 1040attached at distal end 1032 of shaft 1030. Bendable section 1006 of tube1010 can include a spiral wire (or spring-like) structure or a similartubular structure that is flexible. Within bendable section 1006, theexample of FIG. 16 shows shaft 1030 including several hinged sections1031. Shaft 1030 can also be bendable in the vicinity of bending region1006 without having hinged sections.

FIG. 17 shows another embodiment of a surgical instrument 1100 of theinvention. Surgical instrument 1100 includes a rotational cutting bladeat its distal end 1102. Also, instrument 1100 includes a tube 1110 thatis telescopic. Instrument 1100 also includes a shaft (not shown) withintube 1110 that is also telescopic.

FIG. 18 shows instrument 1100 of FIG. 17 having a telescopic tube 1110.FIG. 18 shows shaft 1130 within tube 1110 and extending through handle1150. Shaft 1130 of instrument 1100 is also telescopic.

The instrument of the present invention can be made from materials thatare commonly used for surgical instruments. For example, the tube andthe shaft including the outer and inner blades as previously describedcan be made of stainless steel. The tube and shaft can also be made ofplastic. The handle can be made of plastic or steel. The tubular shapeof the tube and tubular shaft allows the instrument to easily withstandthe torque applied to rotate the tube or shaft.

Also, the tubular design allows for other auxiliary instruments to beused together with the surgical instrument of the invention. Anauxiliary instrument can be slidably inserted through the handle andlumen of the tubular shaft either before or during the surgery. Forexample, an endoscope can be inserted through the instrument so that thesurgeon can observe the body cavity in front of the instrument as heinserts the instrument into the patient's body. After the instrument isplaced as desired, the endoscope can be removed and another instrument,such as a suction or irrigation cannula can replace the endoscope. Thus,fewer incisions need to be made, which is beneficial to the patient.

The present invention also includes a method for cutting body tissue.The method includes inserting a surgical instrument including a tubehaving a distal end, a proximal end, and a longitudinal axis between thedistal and proximal ends into the patient's body. The instrument furtherincludes an outer blade at the distal end of the tube. The instrumentalso includes a shaft having a distal end, a proximal end, and an innerblade at the distal end of the shaft. As previously described withrespect to the various embodiments of the apparatus of the invention,the shaft is rotatably disposed within the tube. Rotation of the shaftwith respect to the tube, or rotation of the tube with respect to theshaft, results in revolving the inner blade about the central axis ofthe tube. As the inner blade revolves about the central axis, the innerand outer blades are rotatably engaged.

The method further includes aligning body tissue that has been selectedto be cut between the inner and outer blades of the instrument. Next,the tube (or the shaft) is rotated about the longitudinal axis such thatthe inner and outer blades engage to cut the body tissue. The method canfurther include electrically energizing at least one of the inner andouter blades wherein the body tissue can be cauterized during cutting.

The method and apparatus described herein can be used in a variety ofsurgical procedures. For example, saphenous vein harvesting is oneprocedure that can be improved by the use of a rotational scissors thatincorporates electrocautery. The method and apparatus of the inventioncan be used at other locations such as, for example, around the femoralartery or the illiac artery. Still other surgeries that can be performedusing the apparatus and method of the present invention includesurgeries of the gall bladder or hernias.

It should be noted that the embodiments of the method and apparatusdescribed herein are exemplary of the present invention and are not tobe construed as limiting the scope of the invention.

What is claimed is:
 1. A surgical instrument comprising: a tube having adistal end and a proximal end, said distal end including a first cuttingedge; and a shaft within said tube, said shaft having a distal end and aproximal end, said distal end of said shaft including a blade, one ofsaid shaft and said tube being rotatable with respect to the other suchthat said blade cooperates with said cutting edge wherein said blade hasan elongated portion having two opposing surfaces and a second cuttingedge on each of said opposing surfaces.
 2. The instrument of claim 1wherein said shaft is coaxial with said tube.
 3. The instrument of claim2 wherein said shaft has an inner lumen.
 4. The instrument of claim 2wherein said shaft has an inner lumen such that an imaging device may beinserted therein.
 5. The instrument of claim 2 wherein said shaft has aninner lumen such that a separate surgical instrument may be insertedtherein.
 6. The instrument of claim 1 wherein one of said first cuttingedge and said blade is adapted to be electrically energized.
 7. Theinstrument of claim 1 wherein said tube is fixedly attached to a handleand said shaft is rotatable relative to said tube.
 8. The instrument ofclaim 1 wherein said blade includes a serrated cutting edge.
 9. Theinstrument of claim 1 wherein said first cutting edge on said tube isserrated.
 10. A surgical instrument comprising: a handle; a tubeextending from and coupled to said handle, said tube having a distal endand a first cutting edge at said distal end, said tube having a proximalend associated with said handle; a tubular shaft defining a lumencoaxial with said tube, said shaft rotatably disposed within said tubeand having at its distal end an elongated portion having two opposingsurfaces and a second cutting edge on each of said opposing surfaces,said opposing surfaces having an insulating layer thereon, said shafthaving a proximal end adjacent said handle and a distal end adjacentsaid distal end of said tube, wherein one of said second cutting edgeson said shaft and said first cutting edge on said tube is adapted to beelectrically energized; and wherein said handle defines an opening incommunication with said lumen of said tubular shaft wherein said openingand said lumen provide access through the instrument to said distal endof said tubular shaft.
 11. The instrument of claim 10 wherein said tubeand said shaft are bendable.
 12. A surgical instrument comprising: ahandle; a tube having a distal end and an outer blade extending fromsaid distal end, said tube having a proximal end associated with saidhandle; and a shaft disposed within said tube, said shaft having adistal end adjacent said distal end of said tube, said shaft having aninner blade extending from said distal end, wherein said inner blade hasan elongated portion having two opposing surfaces and a cutting edge oneach of said opposing surfaces, said opposing surfaces having aninsulating layer thereon, said shaft having a proximal end extendinginto said handle, wherein said inner blade and said outer blade areadapted to be electrically energized.
 13. The instrument of claim 12wherein said tube has a first longitudinal axis and said shaft has asecond longitudinal axis displaced from said first longitudinal axis.14. The instrument of claim 13 wherein said tube is fixedly attached tosaid handle and said shaft is revolvable about said first longitudinalaxis relative to said tube.
 15. The instrument of claim 13 wherein saidshaft is fixedly attached to said handle and said tube is rotatableabout said first longitudinal axis relative to said shaft.
 16. Theinstrument of claim 13 wherein said shaft is revolvable about said firstlongitudinal axis relative to said tube, and said tube is rotatableabout said first longitudinal axis relative to said shaft.
 17. A methodfor cutting body tissue, the method comprising: inserting a surgicalinstrument comprising a tube having a distal end, a proximal end, alongitudinal axis between said distal and proximal ends, and a firstcutting edge at said distal end of said tube, said instrument furtherincluding a shaft having a distal end, a proximal end, and a blade atsaid distal end of said shaft, wherein said blade has an elongatedportion having two opposing surfaces and a second cutting edge on eachof said opposing surfaces, said shaft being rotatably disposed withinsaid tube such that said cutting edge and said blade are rotatablyengageable; aligning the body tissue to be cut between said firstcutting edge and said blade; and rotating at least one of said tube andsaid shaft about said longitudinal axis such that said first cuttingedge and said blade engage to cut the body tissue.
 18. The method ofclaim 17 further comprising electrically energizing at least one of saidfirst cutting edge and said blade wherein the body tissue is cauterized.